吸附色谱常用的吸附剂是______、______和聚酰胺。

A．Exports of natural gas from the U．S． would force the world-wide price of natural gas to an equilibrium and reduce the price of natural gas for consumers in the U．S．

B．Exports of natural gas from the U．S． would result in higher prices for natural gas, benefiting producers and exporters of natural gas in the U．S． and harming consumers of natural gas in the U．S．

C．Exports of natural gas from the U．S． would force the world-wide price of natural gas to an equilibrium which would mean that producers of natural gas in the U．S． could not charge more than the cost to produce the natural gas．

D．The U．S． government would eventually have to prohibit exports of natural gas to foreign countries in order to control the price of natural gas．

A. No effect

B. A decrease

C. An increase

What is said about the U.S. federal funding for research？

A．It has increased by 3 percent.

B．It has been unsteady for years.

C．It has been more than sufficient.

D．It doubled between 1998 and 2003.

A．liabilities increased $5 000; owner's equity, no effect

B．liabilities decreased $5 000; owner's equity increased $5 000

C．liabilities, no effect; owner's equity increased $5 000

D．liabilities, no effect; owner's equity decreased $5 000

What is said about the U.S. federal funding for research？

A．It has increased by 3 percent

B．It has been unsteady for years

C．It has been more than sufficient

D．It doubled between 1998 and 2003

What is said about the U.S. federal funding for research？

A．It has increased by 3 percent

B．It has been unsteady for years

C．It has been more than sufficient

D．It doubled between 1998 and 2003

If the assumption about the delay of a new Ice Age is correct, _____.

A．the increased levels of carbon dioxide could warm up the earth more quickly

B．ice would soon cover the southern hemisphere

C．the best way to overcome the cooling effect would be to burn more fuels

D．the greenhouse effect could work to the advantage of the earth

A．increasing; increasing

B．increasing; decreasing

C．decreasing; increasing

D．decreasing; decreasing

What does the last paragraph in the passage suggest？

A．Mr. Eastman had realized the great effect his camera would have on the world.

B．Mr. Eastman didn't expect his camera would produce such a great effect on the world.

C．Mr. Eastman did hope his camera would affect the world the way he expected.

D．Mr. Eastman was ambitious to expect his camera to have such an effect on the world.

What effect will the increased use of DME instead of diesel fuel probably have？

A. It will reduce the amount of pollutants in the air.

B. It will increase the amount of unpleasant odors from vehicles.

C. It will eventually destroy the ozone layer.

D. It will reduce the cost of running large vehicles.